We should keep ______ in the reading –room.
-What are you going to do this Sunday? -I ________ yet.
—When did you ____ the top of the mountain?—At 11;45 a.m.
—Have you found your watch? —No, it is ______to see anything in the hole.
—Are there any trees on _____ sides of the new street?—Yes, there are.
—____ my pen?—Yes, I ___ it on your desk five minutes ago.